12311381 has 4 divisors (see below), whose sum is σ = 12318432. Its totient is φ = 12304332.

The previous prime is 12311347. The next prime is 12311389. The reversal of 12311381 is 18311321.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 18311321 = 7 ⋅2615903.

It is a cyclic number.

It is not a de Polignac number, because 12311381 - 2¹⁰ = 12310357 is a prime.

It is a super-2 number, since 2×12311381² = 303140204254322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12311389) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1256 + ... + 5118.

It is an arithmetic number, because the mean of its divisors is an integer number (3079608).

Almost surely, 2^12311381 is an apocalyptic number.

It is an amenable number.

12311381 is a deficient number, since it is larger than the sum of its proper divisors (7051).

12311381 is an equidigital number, since it uses as much as digits as its factorization.

12311381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7050.

The product of its digits is 144, while the sum is 20.

The square root of 12311381 is about 3508.7577573837. The cubic root of 12311381 is about 230.9061980551.

The spelling of 12311381 in words is "twelve million, three hundred eleven thousand, three hundred eighty-one".